Noisy kitchen sprayer

I recently installed a new kitchen faucet with a separate sprayer. Since the installation, every time I use the sprayer there's a loud buzzing/humming/vibration noise. If I turn the handle for more water, the volume and pitch of the noise go up, and if I turn the handle for less water the volume and pitch go down and eventually go away... leaving me with very little pressure in the sprayer. I've checked to make sure all the nuts are tight, and they are, but I can't figure out where that noise is coming from. Any thoughts?